In general, blood is composed of blood cells and blood plasma. The blood cells are classes as red blood cell, white blood cell and blood platelet. The blood plasma is mainly composed of water and includes some blood coagulation element and ions.
As mentioned the above, blood is a mixture which includes various elements. In these days, blood extracting technologies for lots of medical uses are widely spread, and especially blood centrifugations are generally used.
The blood centrifugation uses differences of blood elements in weight to separate the elements by rotating the mixture at a high speed. When centrifuging whole blood, the red blood cells which are heaviest move downward or outside to form the lowest layer. On the layer of the red blood cells, layers of white blood cells, plasma and platelets are formed in order.
On the other hand, PRP (Platelet Rich Plasma) in the plasma may be positioned at the lower portion in the blood plasma layer, which can be usefully used specially for blood coagulation or stopping bleeding. Since the PRP contains cytokine, PDCF, TGF-BETA1, VEGP and the like, some research papers or articles reveal that the PRP is good for skin ailment and wound healing.
However, there are some problems that extracting target element like PRP from the whole blood is very complicated and difficult.
In the conventional methods, the red blood cells are separated from the blood through a centrifugation, and the blood platelet can be separated from remained blood through one more centrifugation. Accordingly, extracting platelets from blood needs at least two times of centrifugations, such that it is very inconvenient and complicated. Most of all, the blood should be exposed to the air when transferring the blood in the conventional methods.
In the conventional methods, since it takes too much time for the extraction of target element, it has been very difficult to inject the platelet extracted through at least two times of centrifugations in situ.
In these days, actively pushed are developments for centrifuging blood quickly and simply.